Conventionally, an emergency communication system has been known, which can transmit data such as the present position of a vehicle, registered number of a vehicle, etc. to a center for controlling emergency communication system such as police station, emergency communication center, etc. These data are transmitted via emergency communication conveying means such as a handy phone installed on the vehicle in an emergency, e.g. traffic accident, sudden illness, etc. when a user is driving a vehicle.
However, the conventional type emergency communication system uses a special-purpose radio device, e.g. a handy phone, as the emergency communication conveying means. For the purpose of ensuring the reliable emergency communication operations, the handy phone cannot be removed or detached. In this respect, the handy phone cannot be taken out from the vehicle and used in the same manner as an ordinary type portable telephone although it has normal function as a telephone set. To use the handy phone for such purpose, it is necessary to provide another handy phone.